Question

however, I have been waiting/have waited for a reply for weeks and i still have not received/did not receive any answer.

Answer 1

Ответ:

However, I have been waiting for a reply for weeks and I still have not received any answer.
Объяснение:
▪︎ have been waiting - Present Perfect Continuous, акцентируется внимание на продолжительности действия (for weeks).
▪︎ have not received - Present Perfect , т к указано still - все еще, т.е действие (не) совершилось к настоящему времени. Нам важен результат в настоящем.
Тем не менее я ждал ответа несколько недель и до сих пор не получил его. #SPJ5